Rachel's Sugar Plum Spice Jam

Heat plums, pineapple, orange juice concentrate, apple juice, and lemon juice in a large pot over medium-low heat, covered; cook until plums are soft, 15 to 20 minutes. Mash plums and pineapple with a potato masher until thoroughly broken up, leaving small chunks in mixture.

Bring mixture to slow simmer; stir in pectin, butter (to reduce foaming), cloves, and allspice. Increase heat to high; bring to a full, rolling boil for 1 minute, stirring constantly. Stir in sugar, stirring constantly; cook at a full, rolling boil, 1 minute more. Off heat, stir in red food coloring until evenly colored; skim off any foam.

Sterilize 10 (12-ounce) canning jars and lids in boiling water for at least 5 minutes. Pack jam into hot, sterilized jars, filling to within 1/4 inch of the top. Run a clean knife or a thin spatula around the insides of the jars to remove any air bubbles. Wipe rims with a moist paper towel to remove any residue. Top with lids and screw rings on tightly.

Place a rack in the bottom of a large stockpot and fill halfway with water. Bring to a boil over high heat, then carefully lower jars 2 inches apart into the boiling water using a holder. Pour in more boiling water to cover jars by at least 1 inch. Bring to a rolling boil, cover the pot, and process for 10 minutes.

Remove the jars from the stockpot and place onto a cloth-covered or wood surface, several inches apart, until cool. Once cool, press the center of each lid with a finger to ensure the lid does not move up or down. Store in a cool, dark area.